hugetlb: correctly parse hugetlb.<size>.events files

Signed-off-by: Tomer Lev <me@tomerlev.com>

Author: voidbar

cgroup2/utils.go

@@ -293,6 +293,31 @@ func getStatFileContentUint64(filePath string) uint64 {
 	return res
 }
 
+// Gets uint64 parsed content of key-value cgroup stat file
+func getKVStatsFileContentUint64(filePath string, propertyName string) uint64 {
+	f, err := os.Open(filePath)
+	if err != nil {
+		return 0
+	}
+	defer f.Close()
+
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		name, value, err := parseKV(s.Text())
+		if name == propertyName {
+			if err != nil {
+				log.L.WithError(err).Errorf("unable to parse %q as a uint from Cgroup file %q", propertyName, filePath)
+				return 0
+			}
+			return value
+		}
+	}
+	if err = s.Err(); err != nil {
+		log.L.WithError(err).Errorf("error reading Cgroup file %q for property %q", filePath, propertyName)
+	}
+	return 0
+}
+
 func readIoStats(path string) []*stats.IOEntry {
 	// more details on the io.stat file format: https://www.kernel.org/doc/Documentation/cgroup-v2.txt
 	var usage []*stats.IOEntry
@@ -423,7 +448,7 @@ func readHugeTlbStats(path string) []*stats.HugeTlbStat {
 			Max:      getStatFileContentUint64(filepath.Join(path, "hugetlb."+pagesize+".max")),
 			Current:  getStatFileContentUint64(filepath.Join(path, "hugetlb."+pagesize+".current")),
 			Pagesize: pagesize,
-			Failcnt:  getStatFileContentUint64(filepath.Join(path, "hugetlb."+pagesize+".events")),
+			Failcnt:  getKVStatsFileContentUint64(filepath.Join(path, "hugetlb."+pagesize+".events"), "max"),
 		}
 	}
 	return usage